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Journaled File System or JFS is a 64-bit journaling file system created by IBM. There are versions for AIX, eComStation, OS/2, and Linux operating systems. The latter is available as free software under the terms of the GNU General Public License (GPL). HP-UX has another, different filesystem named JFS that is actually an OEM version of Veritas Software's VxFS. In the AIX operating system, there exist two generations of JFS filesystem that are called ''JFS'' (''JFS1'') and ''JFS2'' respectively.〔(【引用サイトリンク】publisher=JFS for Linux project )〕〔(【引用サイトリンク】publisher=IBM )〕 In the other operating systems, such as OS/2 and Linux, only the second generation exists and is called simply ''JFS''. This should not be confused with JFS in AIX that actually refers to JFS1. == History == IBM introduced JFS with the initial release of AIX version 3.1 in February, 1990. This file system, now called ''JFS1 on AIX'', had been the premier file system for AIX over the following decade and had been installed in thousands or millions of customers' AIX systems. Historically, the JFS1 file system is very closely tied to the memory manager of AIX,〔 which is a typical design for a file system supporting only one operating system. In 1995, work began to enhance the file system to be more scalable and to support machines that had more than one processor. Another goal was to have a more portable file system, capable of running on multiple operating systems. After several years of designing, coding, and testing, the new JFS was first shipped in OS/2 Warp Server for eBusiness in April, 1999, and then in OS/2 Warp Client in October, 2000. In December, 1999, a snapshot of the original OS/2 JFS source was granted to the open source community and work was begun to port JFS to the Linux operating system. The first stable release of ''JFS for Linux'' appeared in June, 2001.〔 The ''JFS for Linux'' project is maintained by a small group of contributors known as the ''JFS Core Team''.〔(JFS for Linux project website )〕 This release of sources also worked to form the basis of a re-port back to OS/2 of the open-source JFS. In parallel with this effort, some of the JFS development team returned to the AIX Operating System Development Group in 1997 and started to move this new JFS source base to the AIX operating system. In May, 2001, a second journaled file system, ''Enhanced Journaled File System (JFS2)'', was made available for AIX 5L.〔〔 Early in 2008 there was speculation that IBM is no longer interested in maintaining JFS and thus it should not be used in production environments.〔(Re: which to use: ext3, JFS, XFS, ReiserFS? )〕 However, Dave Kleikamp, a member of the IBM Linux Technology Center and JFS Core Team,〔 explained that they still follow changes in the Linux kernel and try to fix potential software bugs. He went on to add that certain distributions expect a larger resource commitment from them and opt not to support the filesystem.〔(SourceForge.net: jfs-discussion )〕 In 2012, TRIM Support was added to JFS. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「JFS (file system)」の詳細全文を読む スポンサード リンク
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